For the Hoarder!

For the Hoarder! is awarded to players who complete any of the six primary wings (that is, all but the Twisting Corridors) of Torghast, Tower of the Damned with at least 1000 Phantasma in the bank.

This is easiest on a lower layer. Make sure to kill and loot every enemy, every Ashen Phylactery, and choose any Phantasma rewards from Anima Cells. Don't purchase any items from the broker on floor 3, and make sure to not dip below 1000 Phantasma with purchases from the broker on floor 6, right before the layer boss.